The invention relates to a method for maximizing the throughput of a printer.
Printers, such as the well-known hp LaserJet printers manufactured by the Hewlett-Packard Company of Boise, Id., print upon pieces of various media types (such as cut-sheets or envelopes) that are fed to the print mechanism at a constant fixed rate. Because the print rate, or throughput, is fixed (e.g., at 8 pages per minute), it takes as much time to print on a #7 sized envelope as it does to print on a letter-sized (8.5.times.11.0 inches) cut sheet, despite the fact that their lengths are not similar. It would be more efficient, in terms of time, to increase throughput based on the length of the media to be printed upon. Thus, if letter-sized cut sheets could be printed at a rate of 8 pages per minute, then #7 envelopes could be printed at a much faster rate.
Increased throughput can be affected by the use of a jam sensor commonly employed in the printer feed path. Through the use of the present jam sensor, which is generally located just after the feed rollers at the beginning of the paper path and just after the media has exited the cassette, the leading edge and the trailing edge of any length media can be determined. The leading edge would trip the sensor, by way of a switch arm, and activate the sensor. The sensor would stay in the same state for the length of the media piece being fed for printing.
By queuing the start of the next media piece by the switching of the sensor back to the original state with the passing of the trailing edge of the previous piece, a constant gap between each successive piece could be maintained. Thus, if media pieces were shorter than the pre-selected threshold level of a given printer, then more pieces of media could be fed within a given time period while additionally permitting the printing of consecutive pieces of varied or equal length.